The action of insulin on pyruvate dehydrogenase is being investigated in rat adipose tissue. The purpose is to discover the mechanism by which insulin activates the dehydrogenase. Studies are also being conducted on the hormone-sensitive lipase, particularly the lipase inactivating system, and on cyclic-AMP phosphodiesterase, particularly in relation to the activation of this enzyme by insulin. BIBLIOGRAPHIC REFERENCES: Taylor, S.I., Mukherjee, C., and Jungas, R.L. 1975. "Regulation of Pyruvate Dehydrogenase in Isolated Rat Liver Mitochondria. Effects of Octanoate, Redox State and ATP/ADP Ratio". J. Biol. Chem, 250: 2028-2035. Jungas, R.L. 1975. "Insulin. Part 2. Effects of Insulin and Proinsulin. Metabolic Effects on Adipose Tissue in vitro". In Handbook of Experimental Pharmacology, Vo. 32/2, Ed. by Hasselblatt, A., and Bruchausen, F., Springer-Verlag, Berlin, p 371-412.